Method and apparatus for shattering shock-severable solid substances

ABSTRACT

The improved method and apparatus for shattering, comminuting or reducing the size of shock-severable solid substances or materials, such as ores, minerals and rocks, includes charging a pressure vessel, which forms a first zone, with the solid material, introducing a compressible working fluid into said vessel, and thereafter causing the solid material to be entrained in the expanding working fluid and discharging the entrained material into a second zone of lower pressure though a system wherein the entrained material is continuously subjected to shock phenomena from the time it exits from said first zone until it is discharged into said second zone. The method and apparatus also includes a dual system to impact high velocity material streams against each other to shatter and reduce the size of said solid material. The apparatus injects the working fluid in such a manner and so locates and operates a quick-opening valve so as to prevent significant wear or damage to the valve.

United States Patent Snyder July 22, 1975 [5 METHOD AND APPARATUS FOR3,545,683 12/1970 Schulte 241/5 SHATTERING SHOCK SEVERABLE SOLID3,614,000 10/1971 Blythe 241/5 SUBSTANCES Primary Examiner Granville Y.Custer, Jr. 1 1 lmemml Francis Henry Snyder Newtown, Attorney, Agent, orFirmKenyon 8; Kenyon Reilly Conn- Carr & Chapin [73] Assignee: Lone StarIndustries, Inc.,

Greenwich, Conn. [57] ABSTRACT [22] Filed: Nov. 9, 1973'cl'girellzplrtoyed method and apparatus for shattering, g or reducingthe size of shock-severable [21] App]. No.: 414,195 solid substances ormaterials, such as ores, minerals and rocks, includes charging apressure vessel, which q Apphcauon Data forms a first zone, with thesolid material, introducing [63] Commuanommpa" 9 S May a compressibleworking fluid into said vessel, and z z g l t s g of thereafter causingthe solid material to be entrained in one the expanding working fluidand discharging the entrained material into a second zone of lowerpressure [221 Ccl1 223558 1191432 though a System wherein the entrainedmaterial is com I 241/5 39 40 tinuously subjected to shock phenomenafrom the [58] 0 earc time it exits from said first zone until it isdischarged into said second zone. The method and apparatus also [56]References Cited includes a dual system to impact high velocity materialUNITED STATES PATENTS streams against each other to shatter and reducethe 2,602,595 7/1952 Thomas.. 241/39 size of said solid material. Theapparatus injects the 2.974.886 3/1961 Nagcl 241/39 working fluid insuch a manner and so locates and op- 3J84'169 5/1965 Friedman 241/40erates a quick-opening valve so as to prevent signifi- 3257.080 6/1966Snyder 241/5 Cant wear or damage to the valve 3.352.498 11/1967Schulte..v 241/5 X 3.482.786 12/1969 Hogg 241/40 X 39 Claims, 5 DrawmgFigures my, Ti 1T1.

llo lid PATENTEDJUL 22 1915 SHEET llm METHOD AND APPARATUS FORSHATTERING SIIOCK-SEVERABLE SOLID SUBSTANCES This application is acontinuation-in-part of copending application Ser. No. 361 ,610, filedon May 18, 1973, now abandoned, which latter application is acontinuation of application Ser. No. 170,087, filed Aug. 9, 1971, nowabandoned.

BACKGROUND OF THE INVENTION This invention relates to processing, andmore particularly to improvements in methods and apparatuses forshattering or efiecting size reduction of shockseverable solid materialssuch as ores, minerals and rocks. It is an improvement upon theinvention disclosed in my prior U.S. Pat. No. 3,257,080.

The invention of such prior patent has proven most effective inshattering and size reduction of solid material but the process thereindisclosed does not provide the ideal environment for subjecting thematerial to shock phenomena throughout the entire system which connectsthe first zone with the second zone of said process. Also, thequick-opening valve that initiates the flow from the first to the secondzone is located near the lower end of the vessel forming said firstzone; such location, coupled with the fact that the working fluid isintroduced into the first zone at a point above its lower end, resultsin the material being forced into and contacting the valve while saidvalve is still in the closed position, thereby subjecting the valve toserious abrasive forces and undue wear as the valve is operated.

The present invention improves the shattering process, minimizes valvewear and provides a more economical and reliable process and apparatus.

SUMMARY OF THE INVENTION The method comprises charging a pressure vesselwhich forms a first zone with a solid material of a selected particlesize range, and introducing into said first zone a compressible workingfluid until a desired pressure level is reached. The compressibleworking fluid is then permitted to expand as it is discharged into aduct from the first zone, thereby causing a portion of the workingfluids enthalpy to be converted to kinetic energy and causing theentrainment of the solid material in the expanding fluid andaccelerating it through the length of said duct, after which the mixedstream of fluid and solids is discharged into a second vessel forming asecond zone. The method involves subjecting the solid material to shockphenomena as it exits from the first zone, subjecting it to furthershock phenomena as it flows through the duct and to additional shock asit passes from the duct to the second zone; said method also acceleratesthe material as it flows through and exits from the duct, therebyinducing impact forces which further increase the shattering action andsize reduction of the solids.

The method also subjects the accelerated mixed stream of fluid and solidparticles to comminutive forces initially during flow through the ductby reason of interparticle collision and other forces and subsequentlyupon discharge into the second vessel forming the second zone, either bydirecting the material against a fixed impact surface in said secondzone or by employing a dual system in impacting the high velocity streamof fluid and solid material from one system against the high velocitystream of fluid and solid material of the other system; such collisionoccuring in a common second zone and providing additional forces actingupon the material to effect further shattering and size reduction. Sinceimpact occurs in said second vessel, it is sometimes hereinafterreferred to as an impact chamber.

The apparatus includes means in the region of the connection between thefirst zone and the duct and in the region of the connection between theduct and second zone for creating shock phenomena to produce increasedshattering and size reduction in these areas. A quick-opening valve islocated in the duct between the first and second zones, and the workingfluid which is accumulated in the first zone is principally introducedbetween this valve and said first zone. Such point of working fluidintroduction ensures that the duct is free of solid material prior tothe opening of the valve, and this, together with the location of thequick-opening valve a sufficient distance downstream of the first zone.assures that the valve will have time to move to the fully open positionso that no solid material can strike the valve element, therebypreventing appreciable valve wear, and prolonging the life of the valve.The opening of the valve allows rapid expansion of the working fluidwhich is necessary to the establishment of flow and production of shockphenomena.

The duct which connects the first and second vessels comprises a noveland unconventional nozzle and elongated throat system which can betermed a supersonic nozzle arrangement for mixed streams consisting ofsolids and fluids. Preferably, such system comprises a convergent nozzlesection extending from the first vessel or zone, an elongated throatsection formed by a substantially constant diameter duct and a divergentnozzle section connecting said duct to the second vessel or zone. Aswill be hereinafter explained, the nozzle, and elongated throat, systemproduces greatly improved results in the size reduction of material.

OBJECTS OF THE INVENTION The primary object of the invention is toprovide a method of shattering shock-severable solid materials, byadding a compressible working fluid to a charge of said solids, in afirst zone, causing the solids to be entrained in the expanding workingfluid through a nozzle, and elongated throat, system into a second lowerpressure zone, and subjecting the material to shock phenomena throughoutsaid nozzle, and elongated throat, system that connects the two zones,to produce effective shattering and size reduction of said material.

Another object is to provide an apparatus, of the character described,including a first vessel, a second vessel, a duct between the vessels topermit the material entrained in the working fluid to flow from thefirst to the second vessel, and a convergent nozzle connecting the firstvessel and the duct; said nozzle having a configuration which willpermit rapid expansion and acceleration of the working fluid to highvelocity so that the fluid passing around entrained particles of thesolid material will cause local zones of supersonic flow and createshock phenomena to which the particles will be subjected, therebyeffecting shattering and size reduction of said particles.

A further object is to provide an apparatus, of the character described,wherein a high percentage of the working fluid for entraining thematerial to be shat tered in introduced into the duct at a point betweenthe first vessel and a quick-opening valve so that that portion of theduct between said first vessel and said quickopening valve is sweptclear of solid material; said valve being located a sufficient distancedownstream of said first vessel to permit the valve to reach the fullopen position before any material flowing from the first vessel throughthe duct reaches said valve, thereby obviating any significant abrasionor wear of the valve.

A further object is to provide a shattering system which produces highvelocity streams of solid material which are jetted into an impactchamber or zone; said system lending itself to use in an arrangementwherein one high velocity stream of material may be impacted againstanother high velocity stream of material, whereby the impact forces sogenerated are utilized to increase the shattering effect and the sizereduction of the solid material.

A further object is to provide an apparatus, of the character described,wherein the shape of the second vessel is designed so that it convertsthe three dimensional flow of the mixed stream of working fluid andsolids entering said vessel into a one-dimensional or linimpact chamberare connected by means of a system comprising a convergent section, anelongated throat section, and a divergent section, the throat sectionbeing adapted to produce choked and sonic flow of the mixed stream offluid and solid particles at the entrance to said divergent section,which flow is then accelerated to supersonic velocity as it dischargesthrough the divergent nozzle section to create additional shock effectswhich act destructively on the solids in the jet entering said impactchamber.

A further object is to provide a pressure vessel so designed thatcomplete discharge of the solid materials is achieved.

A particular object of the invention is to provide nozzles whichfunction as supersonic nozzles for a mixed stream consisting of solidparticles entrained in a working fluid, such as steam or the like.

Other objects, features and advantages of this invention will beapparent from the drawings, the specification and the claims.

DESCRIPTION OF THE DRAWINGS FIG. 1 is a schematic view of the apparatusused to perform the method of the present invention.

FIG. 2 is an enlarged view of the duct which connects DESCRIPTION OFFIRST EMBODIMENT OF INVENTION In the drawings the letten A designates afirst vessel or zone which is connected through a special system formedby a duct B with a second zone C. Flow through the duct B is initiatedby a quick-opening valve D. A convergent nozzle section E connects theoutlet of the first zone A with a duct B, while the other end of theduct has connection with the second zone C through a divergent nozzlesection F. The duct B forms an elongated throat section which extendsbetween the con vergent and divergent sections. The convergent sectionE, throat section B and the divergent section F provide a novel nozzle,and elongated throat, system and form the connecting duct B betweenvessels A and C.

Zone A is adapted to receive the solid material which is to be reducedin size. A compressible working fluid, such as steam, is introduced intozone A through an inlet line G having communication with the throatsection B between valve D and convergent nozzle E. During theintroduction of the working fluid, the valve D is in the closedposition. Introduction of the working fluid-into zone A is continueduntil a preselected pressure is reached whereby thermal energy orenthalpy is stored within said zone; the preselected pressure and theratio of fluid to solids are varied in accordance with the desired sizereduction to be accomplished of the particular material being processed.

The term compressible working fluid as used herein, includes not onlysteam but any gas or vapor which is capable of doing useful work uponexpansion. The term solids is used herein interchangeably with the termssolid particles, solid material and solid substance, and refers to thematerial being processed. As used herein, the term severance is employedin the sense stated at pages 1-01 and 1-03 of A. F. Taggarts Handbook ofMineral Dressing (1945), i.e., severance signifies a comminution orbreaking apart of I a solid substance. Shock-severable refers to a solidfer of kinetic energy out of the working fluid and into the solidparticles so that the particles are accelerated to a high velocity bythe time they enter the divergent nozzle-section F; During flow throughthe duct, the solid particles are subjected ,to additional shockphenomena. In..the divergent nozzle section, the mixed stream of fluidand solid particles is accelerated to supersonic flow which subjectssaid particles tofurther shock phenomena. Thereafter the combined fluidand solids stream is directed into the second zone C.

The area of the discharge from the second zone C is sufficiently largeso that there will be no back pressure condition or effect created inthis zone which would be adverse to the efficient production .of thekinetic energy of themixedstream as' it. is discharged into this zone.

From zone C the mixed stream is discharged through a divergent passage Hwhich communicates tangentially with a cyclone separator I. This passageis made divergent in order to decelerate the flow into said cycloneseparator. The working fluid is preferably withdrawn from the separatorI from the upper end, although said fluid or a portion thereof may bewithdrawn from the lower end at a low velocity. The solid material iswithdrawn from the lower end of the separa tor.

The apparatus employed in carrying out this improved method includes apressure vessel which defines a zone A. A solid material loading valve11 and a loading hopper 12 are located at the upper end of said vessel.The loading valve may be actuated by any suitable valve actuator lla,and said actuator may be operated by pneumatic or other means. Thecross-sectional area of the lower end of the vessel 10 is reduced, asgenerally indicated at 13, and has an eccentric outlet 14 which connectswith the larger end of the convergent nozzle section E. The smaller endof said nozzle section is coaxial with the throat section B which isterminated by the nozzle section F and the Coanda surface 21.

The material to be processed is delivered to the feed hopper 12 afterhaving been previously prepared to provide a suitable charge. When thevalve 11 is opened, the material enters the vessel 10 which defines zoneA. The size of the vessel 10 is subject to wide variation and depends onthe scale of operation.

After the desired amount of the solid substance or material has beenintroduced into the charge zone A, the working fluid, which will bereferred to herein as steam, is introduced from a supply line 15,through a control valve 16 and into the inlet line G. A pair of inletports 16a and 16b connect with the inlet line G and extend through theduct B, preferably in diametrically opposed relationship for the purposeof introducing the working fluid into duct B. The use of opposed inletports is desirable because a single inlet might cause the high-velocitysteam to eventually crater or wire-draw the metal of the opposite sideof the duct. The inlet ports 16a and 16b communicate with the duct Bbetween the quick-opening valve D and the convergent nozzle section E sothat the working fluid is introduced through duct B and flows throughthe duct in a direction toward the vessel 10 by reason of the valve Dbeing in the closed position at this time. By injecting the workingfluid in this manner, the line B is swept clear of solid particles andthe working fluid is introduced into the lower end of vessel 10 so as tocreate a spouted bed in vessel 10. The introduction of the working fluidinto the lower end of the vessel also effects a transfer of anyrelatively fine material to the upper portion of said bed. By reverseclassification the jamming of fine material into the discharge zone isobviated.

In actual practice of the invention, a wide range of solids/fluid weightratios may be employed. For example, with saturated steam at 450 psi,the range may vary anywhere up to approximately 200 to l. Thesolids/fluid ratio is determined by the extent to which the vessel 10 isfilled with material to be processed and by the quantity of workingfluid which is introduced. The pressure of the fluid which is introducedinto vessel 10 is also subject to variation over a wide range, usuallyin the range of from 50 to 2,000 psia. The pressure chosen depends uponthe material being processed and the degree of shattering which isdesired.

The valve D is illustrated as a rotary type valve which has its shaft 17connected to a suitable valve actuator 18. The valve is full-ported,that is, when the valve is in its open position, the port or openingtherethrough is identical to the size and shape of the bore of the ductB. As previously noted, the valve is quick opening so that after thematerial has been pressurized in the first zone A, said valve openssubstantially instantaneously to initiate the flow of the mixed streamof fluid and solids.

One of the important features of the present invention is the locationof the valve D downstream from the zone A a sufficient distance so thatthe valve will be fully open before any of the particles of solidmaterial reach the body of the valve. Actual use of this invention hasshown that unless an arrangement is provided to so protect the valve,the force of the solids moving at high velocity through the duct B andagainst the closure member of the valve abrades and damages the valvevery quickly. This valve may be located at any point along the axis ofthe system as long as the criteria set forth in the preceding sentencesare satisfied. In the present instance, the rapid opening of the valve,coupled with the location of the valve well downstream from vessel 10,assures that the valve will be fully open prior to the time that anysolid particles reach or pass through it. This advantage is enhanced bythe fact that the working fluid is introduced through the duct B in adirection opposite to the direction of discharge of the material fromthe vessel 10; such introduction of the working fluid at this pointsweeps the duct free of solid material. Therefore, when the valve issubsequently opened and flow is initiated, the material must travel fromthe vessel 10 to the valve, thereby providing sufficient time for thevalve to move to the fully open position before the solid particlesreach the same. In actual practice, it has been found that satisfactoryresults are obtained if the valve is opened in less than 20 millisecondswhen this valve is positioned about 4 feet downstream.

Upon the valve D being opened, the mixed stream passing from the vessel10 flows through the convergent nozzle section and into the throatsection B. As the mixed stream passes through the convergent nozzlesection E, said nozzle section B permits acceleration of the workingfluid to a high velocity, which is to say that it converts a portion ofthe enthalpy of the said working fluid to kinetic energy in accordancewith the physical laws governing isentropic flow. The entrained solidsare accelerated initially only slightly, whereas the fluid attains itsmaximum velocity at the exit of this convergent nozzle section. The highfluid velocity, relative to the solids velocity, causes local zones ofsupersonic flow to arise on the irregular solid surfaces. Since theselocal zones of supersonic flow are highly perturbed, shock waves ofgreat force are generated in these thin zones; because the supersoniczones are attached, the shocks are also attached to the solids, wherebysaid solids are subjected to this shock phenomena as they flow throughthe nozzle.

As an example of the relative velocities at the exit of convergentnozzle section E into the throat section B the fluid velocity is on theorder of 1100-1200 fps, while the solids velocity is less than 30 fps.Since the fluid velocity, relative to the solids velocity, is more than1100 fps, corresponding to a Mach Number of 0.65 to 0.75, the shockwaves referred to above are generated on the surfaces of the solidparticles. As

noted, since the shocks arise on the irregular solid sur-' faces, theshocks are attached to the solid surfaces, and are propagated throughthe solids, causing failure or rupture along planes of discontinuity.Even small increments of shock energy are effective because ofaccumulated fatigue that results in failure of interfacial bonds whenthe total accumulated shock energy exceeds the bond energy.

The convergent nozzle section E is subject to considerable variation asto its shape, including its size and length; in actual practice, it hasbeen found that it may have an area ratio of its large end to its smallend of from 3 to l to 8 to 1, preferably about 4 to 1. Its design mustprovide for a smooth entry to the nozzle and a well rounded convergingsection discharging into throat section B. It is preferable that saidnozzle be formed as an eccentric type nozzle, as shown in FIG. 2, sothat the lower portion of the nozzle wall lies in the same plane as thelower wall portion of the vessel outlet 14 and the lower wall portion ofthe throat B, thereby assuring a smooth uninterrupted flow of the mixedstream from the lower end of vessel 10, through said nozzle section Eand into said throat section B.

As the mixed stream travels through the throat section the solids aresubjected to further shock phenomena due to the working fluiddecelerating at a faster rate than the entrained solids accelerate andcreating local zones of supersonic flow. During the entire travel of themixed stream through the elongated throat section B the solids velocityincreases and the fluid velocity decreases. In a throat section ofoptimum length the entire flow is at nearly uniform speed at the end ofsaid throat. As the mixed stream enters divergent nozzle section F, thefluid is further accelerated in said divergent nozzle section and thesolids are accelerated at the expense of most of the added kineticenergy obtained by the additional isentropic expansion of the fluid inthe divergent nozzle. This expansion is adiabatic, in the sense that noheat is added. Since, at least theoretically, the system may bereversible, this will be treated as isentropic expansion. From thenozzle F, the stream is discharged into the second zone C which isformed by a volute shaped receiving vessel or chamber 19. The secondzone is herein referred to as an impact chamber and may have an impactor target plate 20, as shown in dotted line's in FIG. 1, located thereinin the path of the mixed stream which is discharging into the vessel.

The divergent nozzle section F is generally conical, although it may beparabolic, and its length and arearatio are dictated by the lawsgoverning isentropic flow processes. Since fluid expansion, as such, canmake little or no contribution to the effectiveness of the process, thedivergent nozzle section is made as long as possible by restricting thehalf-angle of divergence to a preferable range of 4 to 7 and preferablyabout This provides a sufficient length and time of contact for kineticequilibrium between the phases to be established or closely approached.The solids being now immersed in a supersonic fluid perturb thesupersonic flow with resulting shocks arising on and around the solidparticles, thus subjecting them to additional comminutive forces.

From the divergent nozzle section F, the mixed stream flows across theflared inlet or Coanda surface 21. Such Coanda surface diverts asignificant portion of the fluid and the fine material in a directionapproximately at a right angle to the major axis of the nozzle. Theentire jetted stream is discharged into the volute shaped chamber 19which forms the zone C. As stated, the impact or target plate 20 may beemployed in the chamber C and has its face disposed in a plane normal tothe axis of the duct B. It is spaced a sufficient distance from thenozzle F so that it will not interfere with flow of the mixed stream butis sufficiently close to assure that the central portion of the highvelocity stream will impact against it. Thus, in addition to the othershock phenomena to which the particles are subjected, said-particles aresubjected to impact forces which effect further size reduction. It isbelieved that as the material moves through the duct B, radialclassification of the solid particles occurs with the larger particlestending to be concentrated at or near the center or axis and the smallerparticles moving along the walls. By providing an impact plate which hasits surface located so that the larger particles being ejected from saidduct at a high velocity will strike the same, said particles aresubjected to high impact forces. This causes additional fracturing orshattering by reason of elastic rebound of the particles and impingementof the particles against each other.

The fine material and the boundary layer which are being discharged fromthe throat section at high velocity tend to cling to the inner surfaceof nozzle F and to the Coanda surface 21, thereby diverting a portion ofthe working fluid and said fines outwardly from the axial direction asthe jetted stream enters the vessel 19. The heavier solids collide withthe plate 20, and with themselves.

By observing FIG. 3, which is a corss-sectional view of the voluteshaped impact chamber 19, it will be evident that the jetted streamenters the chamber parallel to the axis of generation of the volute. Thefluid and solids will move randomly after initial entry into the volute'chamber and some of the particles will strike the inner wall of saidchamber to subject them to further impact. The volute shape of thevessel imparts a rotary motion to the fluid and comminuted solids sothat said fluid and solids are directed to the outlet end 19a of saidchamber in linear subsonic flow.

From the volute shaped vessel 19 which forms the impact or receivingzone C, the working fluid and comminuted solids move downwardly throughthe divergent passage H and into the cyclone separator I. Separationoccurs with the solids being preferably discharged downwardly through adischarge pipe 24 and the working fluid being conducted upwardly throughan outlet pipe 25.

In operation,-the ore or other material to be processed is introducedthrough the feed hopper 12, through the loading valve 11 and into thepressure vessel 10. After pressure vessel 10 is charged with the solidmaterial, valve 11 is closed and working fluid inlet valve 16 opens toadmit the working fluid through the line G into'throat B and then intothe lower end of vessel 10. If desired, some portion of the workingfluid may be introduced through an auxiliary line 15a which connectswith the upper end of the vessel 10, with flow through said line beingcontrolled by a valve 15b. The introduction of working -fluid iscontinued until the pressure within vessel-10 has "reached the desiredoperating pressure, whereuponvalves 16 and 15b close. It

is preferable that the introduction of steam be as fast as possible tominimize condensation.

The quick-opening valve D in the duct B is opened, either simultaneouslywith closing of valves 16 and 15b, or immediately thereafter, to connectbetween the lower end of zone A and the duct B. When valve D is firstopened, the solid particles in the lower end of vessel 10 aresubstantially at rest while the working fluid immediately flows throughthe nozzle section B and into the throat section B'. In doing so, itflows around such particles at a high velocity. The relative velocity ofthe working fluid to the solid particles results in a transoniccondition which may be defined as one wherein local zones of supersonicand sonic and subsonic flow occur together in the stream. The supersoniczones arise on the surfaces of the solid particles which are impinged bythe flow of the working fluid. As is well known, shock waves alwaysoccur in these supersonic zones because the flow is densely populatedwith compression waves propagating downstream. The compression wavesovertake each other to produce shock waves so that the solid material issubjected to shocks that arise in the supersonic zones that are attachedto solid surfaces.

When shocks are transmitted into a solid and come to a discontinuity,such as crystal face, fracture plane or fatigue plane, half of theincident shock is reflected backward while the other half of theincident shock is transmitted forwardly through the material. Theamplitude and velocities of the reflected and transmitted shocks dependson the nature of the solids on either side of the discontinuity.Incident shocks are partly reflected and partly transmitted from andthrough such discontinuities with the result that such interfaces areplaced in tension. It is believed that the effectiveness of theshattering system herein disclosed is mostly likely due to the fact thattypical shock-severable materials are far weaker in tension than theyare in compression; when acted upon in the foregoing manner, solidparticles are more readily shattered or reduced in size than whenreduction is attempted by conventional crushing or milling. This notonly produces a shattering but because the forces that separate thesolids into individual crystals or grains are predominately tensional,there is very little tendency for the grains themselves to be fracturedand there is little tendency for incomplete separation at crystalboundaries to occur. Therefore the process produces a clean and discreteseparation of the grains of the material.

At the entry to the throat section B of duct B, the fluid velocity is atmaximum whereas the solid material is just beginning to accelerate. Aspreviously explained, this high relative velocity of the fluid to thesolids results in transonic flow wherein local zones of supersonic,sonic and subsonic flow occur together. Supersonic zones arise on thesurface of the solids and create shock waves that are attached to theparticles and which propagate through the solids causing rupture atareas of discontinuity or fatigue.

By providing a throat section B of sufficient length and ofsubstantially the same cross-sectional area throughout that length,kinetic energy is transferred from the fluid to the solids and the mixedstream attains a very high velocity. It is essential to acelerate themixed stream to a very high velocity so that as it is ejected into thedivergent nozzle section F, shock phenomena will occur on the solids inthe nozzle F. Additionally, if an impact plate 20 is located in zone C,the high velocity impact will increase the size reduction.

The mixed stream leaves throat B at the sonic velocity of thatparticular type of stream. Therefore, the flow in the nozzle F, becomessupersonic and shock waves are created on the solids which subject theparticles to further forces which reduce their size. As the stream movesthrough the nozzle, the fluid expands to its limit and is discharged atsupersonic velocity into zone C.

If an impact plate 20 is employed in zone C, the larger particles in themixed stream which tend to concentrate at or near the axis of the streamare forcibly impacted at high velocity against the plate. Such impactnot only further breaks up or shatters the particles but also results inelastic rebound resulting in interparticle collision as the particlesbounce back from the impact surface. This increase impingement of thelarger particles against each other and effects additional sizereduction. The volute shaped chamber 19 induces rotary motion of thefluid and comminuted material and directs them to the outlet 19a.

From the zone C the fluid and particles are conducted by means of thedivergent passage H downwardly into the cyclone separator I. Within thecyclone, the particles are separated and discharged through a dischargeline 24, while the working fluid escapes through an upper outlet 25.

As has been noted, this system has been proven to provide an effectivesupersonic nozzle for mixed streams consisting of solids and fluid. Infurther explanation of the operation of the invention, it is pointed outthat after the pressure vessel A is loaded, the introduction of theworking fluid into such vessel is continued until a preselected pressureis reached whereby a supply of thermal energy (enthalpy) is storedtherein; the preselected pressure is varied in accordance with thedesired ratio of fluid to solids, this ratio being the controllingparameter so far as the extent of size reduction is concerned. Thepressure is a measure of the quantity of fluid in the pressure vessel;the enthalpy of the steam is the measure of its total energy per unitmass. The decrease in the enthalpy is the measure of the available workwhich can be done on the solid materials. The kinetic energy is equal tothe reduction of the enthalpy; in terms of work the only energy ofinterest is kinetic energy.

The pressure chosen depends upon the desired or required solids/steamweight ratio; pressure, as such, is not a measure of the availableenergy. When the valve is opened, the mixed stream is subjected to shockphenomena in the convergent nozzle section B and is subjected to furthershock phenomena as it travels through the duct B. At the entry toelongated throat B, the fluid velocity is at maximum, whereas the solidsare just beginning to accelerate. However, during the entire travel ofthe mixed stream through the elongated throat section, the solidsvelocity increases and the fluid velocity decreases since the energy ofthe fluid is distributed or partitioned among the several masscomponents of the flow.

As illustrated, the divergent nozzle section F is generally conical,although it may be parabolic and its length and area-ratio are dictatedby the laws governing isentropic flow processes. Since fluid expansion,as such, would make little or no contribution to the effectiveness ofthe process, the divergent nozzle section is made as long as possible byrestricting the half-angle of divergence to the lower practical limit,which is about This provides a sufficient length and time of contact forkinetic equilibrium between the phases to be established or closelyapproached. The solids being immersed in a supersonic fluid perturb thesupersonic flow with resulting shocks arising on and around the solidparticles, thus subjecting them to additional comminutive forces.

The mixed stream leaves the throat section B at sonic velocity for thatparticular system. The speed of sound in the mixed fluid is not the sameas in the fluid alone. For any particular fluid such as stream or air,the sonic speed is given by: a ['yg RT] where g 32. I 74; 'y= ratio ofspecific heats; R specific gas constant; and T is the stream temperaturein degrees R. Knowing the initial or stagnation temperature T,,, we canwrite:

In a two-phase system, we can write:

where r is the solids/fluid weight ratio. Therefore, the flow in thedivergent nozzle section F becomes supersonic and shock waves arecreated which subject the particles to further forces which reduce theirsize. As the stream moves through the nozzle, the fluid expands furtherand is discharged at supersonic velocity into the impact chamber C.

Upon leaving the divergent nozzle section F, the stream flows across theCoanda surface which, as has been explained, hsa the function ofdiverting the boundary layer and, by over-expansion, decelerating theflow through shock to low subsonic velocity. The boundary layer containsa large population of the very small particles created in the systemwithout the forces of terminal impact having been applied. The high rateof deceleration protects the fines from further or excessivecomminution.

In connection with the impact which occurs within the impact chamber,the particles at the center of the stream are subjected to high terminalimpact forces. Additional fracturing or shattering occurs by reason ofelastic rebound of the particles and impingement of these by oncomingsolids in the stream. A large stagnation pressure results when a highvelocity jet is brought to rest, all of the kinetic energy beingconverted back to enthalpy. In other words, the fluid, when stagnated,approaches its initial state. The stagnation temperature is higher thanthe supply temperature, the enthalpy is equal and the pressure is lessbecause of dissipative effects such as friction and work doneexternally, i.e., such as the rupturing of interfaces between crystals.

Although it is believed that the size reduction and comminution of thesolids is caused primarily by reason of subjecting the solids to shockphenomena throughout the system, some assistance may be obtained byreason of thermal shock. Where steam is employed as the working fluid,heat is conducted into the material and as the process progresses, theutilization of some of this heat in expanding the surface layers of theparticles may be a cause of incipient failure or fracture.

SECOND FORM OF THE INVENTION vergent nozzle F. The second systemidentified by'the Roman numeral Il includes the same elementsfA, B, D,

E and F. The dual system utilizes a commonj'receivin zone or impactchamber which is identified-by the let ter C. Y v

Systems I and II have their respective nozzle section F communicatingwith said common impactjc-hatiber 7 zone C. The zone C is formed by avolute shapedves se] 1% similar in design to the chamber l9, excjept'that it provides for connection of the two nozzle sections F in opposedrelation on opposite sides of the volute.

Within the interior of chamber 19b, there are located two deflectorplates 26 and 27 (FIGVS) which are located in spaced relation to eachother and are also located in spaced relation to the end of thenozzlesF. Each plate is provided with a central opening 28' which may have anannular insert 29 of hardened material mounted therein. The deflectorplates'26 and 27 have their openings 28 axially aligned with the axis oftheir respective nozzles F which discharge into the zone C.

The plates are close enough to the ends of the nozzles to assure thatthe central portion of each jetted stream passes through openings 28 andcollides with the opposing jetted stream. The spacing between the platesis not critical but they should be far enough apart to permit free flowof material from between the plates after collision has occurred.

As has been noted, the travel of the solids through each duct B at ahigh velocity classifies such solidsfradially so that the major portionof the larger particles are concentrated in or near the axis or centralpart of each duct. As explained, the finer material-and a portion of thefluid which together comprise theboundarylayer tends to cling to theCoanda surfaces 21 and is diverted radially outwardly. With properlocation of the ends of the deflector plates 26 and 27 relative tonozzles-F, the central portion of each jetted stream will pass throughthe opening 29 of its deflector plateand collide with the other jettedstream. Since the streams are travelling at a high velocity as theyenter the zone C, it will be seen that the collision between the twocentral portions of the streams will perform a large amount ofadditional work in reducing the size of the particles. The deflectorplates also function to deflect the smaller particles which strike theplates in a direction radially outwardly of the axis thereof.

As described herein, the systems employ a fastoperating, quick-openingvalve in the duct which connects the first zone to the second zone. Itis important that there be a sudden opening of the duct and although thevalve is preferable, it is evident that other devices, such as a burstdiaphragm could be employed. Where a burst diaphragm is used, thediaphragm would be constructed to withstand a preselected pressure whichwould be the pressure to which the material is subjected in the firstzone; upon such preselected pressure being reached, the diaphragm wouldrupture to suddenly open the duct and permit flow therethrough, ashereinbefore described.

The foregoing disclosure and description of the invention areillustrative and explanatory thereof and various changes in the size,shape and material, as well as in the details of the illustratedconstruction, may be made with the scope of the appended claims withoutdeparting from the spirit of the invention. To illustrate relative sizesof operative embodiments, however, the following are examples ofprototype units constructed according to the teachings of thisapplication.

The prototype units include four pressure chamber sizes: 0.05, 0.49,2.23, and 6.50 cubic feet. They also include three nozzle system sizes,having nominal throat internal diameters of 1, 2, and 4 inches,respectively. The relevant dimensions of each nozzle system are given inthe table below:

The largest size of feed that can be handled by each system depends inpart on the type of material and its shape (whether oblong or ofrelatively uniform dimensions). Best results in the one-inch system havebeen obtained with materials passing a A-inch mesh screen. Best resultsin the four-inch system have been obtained with materials passing a l/z-inch screen, although materials having dimensions up to 2 inches havebeen tested.

What is claimed is:

1. An apparatus for reducing the size of shockseverable materialcomprising,

a first vessel for receiving the material and defining a first zone,

a second vessel defining a second zone,

a duct extending from the first vessel to the second vessel,

a quick-opening valve in said duct,

means for introducing a predetermined amount of a compressible workingfluid into the first vessel including an inlet in said duct adjacent tosaid valve for introducing at least a substantial portion of saidpredetermined amount for carrying any of said material in the duct backto the first vessel.

means for closing said valve during the introduction of said fluid intothe first zone,

means for opening the valve suddenly to discharge a mixed stream ofworking fluid and material from said first vessel into the duct, whichconducts said stream to the second vessel,

means located between the first vessel and duct for creating a zonewherein the solid material is subjected to shock phenomena as it exitsfrom the first vessel and enters said duct to thereby shatter and reducethe size of said material,

said quick-opening valve being located a predetermined distance from thefirst vessel, and

the spacing of the valve from said first vessel and the time of openingsaid valve being such that said valve moves to fully open positionbefore the material discharged from said first vessel reaches saidvalve.

2. The method of reducing the size of shockseverable solids comprising,

introducing a charge of said solids into a pressure vessel,

introducing a compressible working fluid into the pressure vessel untila preselected pressure is attained in said vessel,

directing a mixed stream of the working fluid and solids into acontinuous nozzle system which extends from said pressure vessel to animpact chamber through the successive steps of converging the mixedstream in a converging section of the nozzle system, therebyaccelerating the working fluid portion of the mixed stream relative tothe solids,

directing the mixed stream through an elongated throat section of thenozzle system having a constant area equal to the minimum area of theconverging section and a length sufficient to accelerate the solids ofthe mixed stream relative to the working fluid portion until maximumkinetic energy has been transferred from the working fluid to the solidsand the stream reaches the sonic velocity of the fluid-solids mixture;

diverging the mixed stream approximately isentropically at supersonicvelocities in a diverging section of the nozzle system and dischargingthe mixed stream of working fluid and solids as a free jet into theimpact chamber after passage through the nozzle system, the pressure inthe impact chamber remaining approximately constant.

3. The method set forth in claim 2, with the additional step ofimpacting the solids in the free jet against a rigid surface within theimpact chamber.

4. The method set forth in claim 2 further comprising the step ofseparating the lighter solids and boundary layer of fluid from thecentral portion of the mixed stream discharging as a free jet into theimpact chamber by flow over a Coanda surface connected to the downstreamend of the diverging section of the nozzle system.

5. The method set forth in claim 2, further comprising the step ofdirecting the mixed stream of working fluid and solids from the pressurevessel into the nozzle system through an eccentric lower end of saidpressure vessel.

6. The method set forth in claim 2 comprising the further step ofdischarging the mixed stream of fluid and solids from the impact chamberinto a cyclone separator through a divergent passage to decelerate theflow.

7. The method set forth in claim 2, wherein at least a substantialportion of the total working fluid introduced into the pressure vesselis introduced through an inlet into the nozzle system downstream fromthe converging section.

8. The method of reducing the size of shockseverable solids comprising,

introducing a charge of said solids into a pressure vessel,

introducing a compressible working fluid into the pressure vessel untila preselected pressure is attained in said vessel,

releasing a mixed stream of working fluid and entrained solids from saidvessel into a nozzle system which extends from said pressure vessel to achamber, said nozzle system comprising successively a convergingsection, an elongated throat section and a diverging section,

said system functioning to rapidly accelerate the working fluid and lessrapidly accelerate said entrained solids to create shock phenomena asthe working fluid and solids pass through the converging section,

said elongated throat section having a length suffrcient for the fluidto transfer maximum kinetic energy to the solids entrained therein andto accelerate the solids to the sonic velocity of the mixture as themixed stream of fluid and solids flows through the elongated throatsection,

said system functioning to further accelerate the fluid and solids asthe mixture flows through the diverging section, and

discharging the mixed stream of fluid and solids as a free jet into achamber after passage through the nozzle system for subjecting thematerial to further shock phenomena. 9. The method set forth in claim 8comprising the additional step of impacting the solids against a rigidsurface within the chamber.

10. The method set forth in claim 8 further comprising the step ofseparating the lighter solids and boundary layer of fluid from thecentral portion of the mixed stream discharging as a free jet into thechamber by flow over a Coanda surface connected to the terminus of thediverging section of the nozzle system.

11. The method set forth in claim 8 further comprising the step ofdischarging the mixed stream of working fluid and solids into the nozzlesystem from the pressure vessel through an eccentric lower end of saidpressure vessel.

12. The method set forth in claim 8 comprising the further step ofdischarging the mixed stream of fluid and solids from the chamber into acyclone separator through a divergent passage to decelerate the flow.

13. The method set forth in claim 8, wherein at least a substantialportion of the working fluid introduced into the pressure vessel isintroduced through an inlet into the nozzle system downstream from theconverging section.

14. The method of reducing the size ofparticles of a shock-severablesolid material charged into a pressure vessel comprising,

adding to the solid particles a predetermined quantity of a compressibleworking fluid in the pressure vessel until a predetermined pressure isattained suddenly expanding a stream of the working fluid and solidsfrom said vessel into a continuous nozzle system which extends from thepressure vessel to a chamber so that the particles of solid material areentrained in the fluid stream, said nozzle system comprising aconverging section, an elongated throat section and a diverging section,

directing the stream from the pressure vessel through said convergingsection of the nozzle system for increasing the velocity of the workingfluid to a maximum value at the entrance to the elongated throat sectionto generate shock waves which act upon the particles of said material toreduce their size,

directing the mixed fluid and solid stream through said elongated throatsection until maximum possible transfer of kinetic energy from the fluidto the solid particles has been achieved, the velocity of the combinedpolyphase fluid and solid mixture attaining the sonic velocity of saidmixture at the downstream end of the throat section, and

directing the mixed stream through the section into a chamber foraccelerating the fluid and the solid particles in themixed stream tosupersonic velocities said chamber having a sufficiently large exit areato permit free expansion of said fluid with minimal stagnation pressurein said chamber.

15. The method set forth in claim 14 wherein the elongated throatsection has a substantially constant cross-sectional area.

16. The method of reducing the size of particles of a shock-severablesolid material comprising,

entraining said particles in a stream of compressible working fluid,

accelerating said fluid at a faster rate than said particles within aconverging boundary surface, then further accelerating said particlesand decelerating said fluid within an elongated continuation of saidboundary surface having substantially constant cross section untilmaximum transfer of kinetic energy from the fluid to the solid particleshas been achieved and the velocities of the particles and fluid aresubstantially equal to the two-phase sonic velocity of said mixedstream, I

then still further accelerating said fluid and said particles tosupersonic velocities in a diverging continuation of said boundarysurface, and l discharging said particles and fluid into a chamber,

whereby said particles will be subject to shock phenomena at each stageof acceleration of said particles. 17. The method of reducing the sizeof shockseverable solids comprising,

introducing a charge of said solids into a first pressure vessel,

introducing a compressible working fluid of predetermined quantity'andpressure into the pressure vessel,

directing a mixed stream of fluid and solids into a first nozzle systemwhich extends from said pressure vessel to an impact chamber maintainedat approximately said second pressure, said first nozzle systemcomprising a converging section, an elongated throat section and adiverging section, the length of the throat section being sufficient topermit maximum transfer of kinetic energy from the fluid to the solidsso that the velocities of said fluid and solids equal the sonic velocityin the mixed stream at the downstearn end of the throat section,subjecting the stream to shock phenomena as it flows from the pressurevessel to the impact chamber, discharging said stream asa free jet intosaid impact chamber at a high velocity, introducing a charge of saidsolids into a second pressure vessel, 7 introducing a compressibleworking fluid of predetermined quantity and pressure into the secondpressure vessel, directing a mixed stre arn of fluid and solids into asecond nozzle system which extends from said second pressure vessel tothe impact chamber,

said second system comprising a converging section,

an elongated non-divergent throat section and a diverging section, thelength of the throat section being sufficient to permit maximum transferof kinetic energy from the fluid to the solids so that the velocities ofsaid fluid and solids equal the sonic velocity in the mixed stream atthe downstream end of the throat section,

subjecting the stream to shock phenomena as it expands at supersonicvelocity through the diverging section to the impact chamber,

discharging said stream as a free jet into said impact chamber at a highvelocity,

and selectively impacting the coarser portion of the solids dischargingfrom the first system against a similar portion of the solidsdischarging from the second system to further reduce the size of thesolids.

18. The method set forth in claim 17, with the additional step ofdeflecting the finer portion of the solids and the boundary portion ofthe working fluid discharging as free jets from the diverging sectionsof the nozzle systems radially outwardly and away from the impact zoneby means of Coanda surfaces. 19. The method set forth in claim 17,wherein said solids are subjected to said shock phenomena as they passthrough said nozzle systems by directing said solids through saidconverging sections which direct the flow from the pressure vessels intothe elongated throat sections, and

said solids are subjected to further shock phenomena in the region ofthe exits from the systems by directing said solids through saiddiverging sections which direct the flow from said throat sections intothe impact chamber.

20. The method of claim 17, wherein the impact chamber has asufficiently large exit area to permit free egress of said fluid, withno general increase of the pressure in said chamber.

21. An apparatus for reducing the size of particles of a shock-severablesolid material comprising,

a pressure vessel for receiving the particles,

an impact chamber,

a system extending from the pressure vessel to the impact chamber,

said system comprising a convergent nozzle section,

an elongated throat section and a divergent nozzle section opening intothe impact chamber,

a quick-opening valve in said system,

means for introducing a predetermined amount of a compressible workingfluid into the pressure vessel when the valve is closed that issufficient to create sonic flow at the downstream end of the elongatedthroat section of a mixed stream of working fluid and particles ofmaterial when the valve is opened, the length of the elongated throatsection being sufficient to permit maximum transfer of kinetic energyfrom the fluid to the particles of solid material in the mixed stream,and

means for opening the valve to suddenly discharge a mixed stream ofworking fluid and particles of solid material from said vessel throughthe system wherein shock phenomena act to shatter and reduce the size ofsaid material.

22. An apparatus as set forth in claim 21 comprising a discharge passagefrom the pressure vessel eccentric to the principal axis of said vesselconnecting the pressure vessel to the larger end of the convergentnozzle section.

23. An apparatus as set forth in claim 21, wherein the valve ispositioned in the elongated throat section and the means for introducinga compressible working fluid into the pressure vessel comprises an inletduct connected into the system between the valve and the convergentnozzle section.

24. An apparatus as set forth in claim 23, wherein the means forintroducing a compressible working fluid comprises two ducts enteringsaid system in opposed relationship.

25. An apparatus as set forth in claim 21 further comprising a Coandasurface forming a smoothly flaring connection between the outlet of thedivergent nozzle section and the impact chamber.

26. An apparatus as set forth in claim 21 further comprising a separatorand a divergent passage connecting the impact chamber to the separatorfor decelerating the fluid passing from the impact chamber to theseparator.

27. An apparatus as set forth in claim 21, wherein said convergentnozzle section has its larger end connected with the pressure vessel andits smaller end connected with the throat section, the length andconfiguration of the convergent nozzle section being such that afterintroducing said predetermined amount of compressible fluid into thepressure vessel and upon opening of the valve, the working fluid expandsto attain a velocity sufficient to cause local zones of supersonic flowattached to the slower moving solid particles whereby the solids aresubjected to shock phenomena resulting from the perturbation of saidlocal zones of supersonic flow.

28. An apparatus as set forth in claim 21, wherein said elongated throatsection is of substantially constant cross-sectional area throughout itslength, and

the divergent nozzle section connects the throat sec- 40 tion with theimpact chamber and is constructed to further increase the velocity ofthe stream as the mixed stream is discharged into the impact chamber.

29. An apparatus for reducing the size of shockseverable solidscomprising,

a convergent nozzle section,

an elongated throat section of constant area having one end connected tothe smaller end of the convergent section, a divergent nozzle sectionhaving its smaller end connected to the other end of the throat section,and

means for supplying a subsonic stream of said solids entrained in acompressible working fluid to the larger end of said convergent nozzlesection for flow through said sections, the pressure of said workingfluid at the entrance of the convergent nozzle section being sufficientto accelerate the mixture to attain sonic velocity at the downstream endof the throat section, the throat section being long enough to assuremaximum transfer of kinetic energy from the fluid to the solids, and thedivergent nozzle section being constructed to accelerate the mixedstream to supersonic velocities.

30. An apparatus for reducing the size of a shockseverable materialcomprising,

a pressure vessel for receiving the material,

an impact chamber,

a system extending from the pressure vessel to the impact chamber,

a quick-opening valve in said system,

means for introducing a compressible working fluid into the pressurevessel,

said valve being in closed position during the introduction of saidfluid into the pressure vessel,

means for opening the valve to suddenly discharge the mixed stream ofworking fluid and material into the system which conducts said stream tothe impact chamber,

means located in the system downstream of the pressure vessel adapted tosubject the solid material to shock phenomena to thereby shatter andreduce the size of said material,

said quick-opening valve being located a predetermined distance from thepressure vessel,

the compressible working fluid being introduced into the system betweensaid valve and said pressure vessel, whereby such working fluid flowsinto the vessel through the system in a direction opposite to that inwhich the material is discharged from said vessel, and

the spacing of the valve frorm said pressure vessel and the time ofopening of said valve being such that said valve moves to fully openposition before any of the material discharged from said pressure vesselreaches said valve.

31. An apparatus for reducing the size of particles of shock-severablesolid material comprising,

first and second pressure vessels for receiving the particles ofmaterial,

an impact chamber positioned between the pressure vessels,

a separate nozzle system extending from each pressure vessel to theimpact chamber with the axis of one system intersecting the axis of theother system in the impact chamber,

each system comprising in continuous succession a converging section, anelongated constant area throat section and a diverging section,

a quick-opening valve in each of said systems,

means for introducing a compressible working fluid into each of saidvessels while said valves are closed, and

means for simultaneously opening the valves to suddenly discharge mixedstreams of working fluid and material from each of the pressure vesselsthrough the respective systems into the impact chamber from opposingdirections, the pressure of said working fluid at the entrance of theconvergent nozzle section being sufficient to accelerate the mixture toattain sonic velocity at the downstream end of the throat section, thethroat section being long enough to assure maximum transfer of kineticenergy from the fluid to the particles of solid material, and thedivergent nozzle section being constructed to accelerate the mixedstream to supersonic velocities for discharge as a free jet into theimpact chamber,

whereby shock phenomena shatter and reduce the size of said particles inthe nozzle systems and further reduction of the size of the particles iscaused by collision of the interseting streams of particles dischargedfrom the two nozzle systems in the impact chamber.

32. An apparatus as set forth in cliam 31 further comprising dischargepassages from the pressure vessels to the respective nozzle systems thatare eccentric to the principal axis of each of said vessels.

33. An apparatus as set forth in claim 31, wherein the quick-openingvalves are positioned in the elongated throat sections of each systemand the means for introducing a compressible working fluid into thepressure vessels is comprised of inlet ducts opening into the systemsbetween the valves and the convergent nozzle sections.

34. An apparatus as set forth in claim 33, wherein said fluid inletducts comprise at least two ducts opening into each nozzle system inopposed relationship to reduce erosion from wire-drawing by the incomingfluid.

35. An apparatus as set forth in claim 31 further comprising Coandasurfaces between the ends of the divergent nozzle sections and theimpact chamber.

36. An apparatus as set forth in claim 31 further comprising a separatorand a divergent passage connecting the impact chamber to the separatorfor decelerating the fluiid and solid particles passing from the impactchamber to the separator.

37. An apparatus as set forth in claim 31 further comprising twodeflector plates spaced from the discharge end of each nozzle system andlocated in said impact chamber, each deflector plate having a centralopening so that the particles in the central portion of one dischargedjet may collide with the particles in the central portion of the otherjet while the remainder of each jet is deflected away from the collisionregion.

38. A method of reducing the size of shock severable solids comprisingthe steps of:

entraining particles of said solids in a stream of compressible workingfluid surrounded by a cylindrical boundary surface;

directing the mixed stream of fluid and solid particles through aconverging boundary surface, thereby accelerating the fluid at a fasterrate than the solids;

then directing the mixed stream in a straight line through an elongatedcylindrical boundary surface equal in cross section to the downstreamend of the converging boundary surface until maximum transfer of kineticenergy from the fluid to the solid particles has been achieved and thevelocities of the particles and fluid are substantially equal to thetwo-phase sonic velocity of said mixed stream, and discharging saidparticles and fluid into a chamber.

39. An apparatus for reducing the size of shockseverable solidscomprising:

a converging nozzle section,

an elongated throat section of constant area extending in a straightline from the smaller end of the converging nozzle section, and

means for supplying a subsonic stream of said solids entrained in acompressible working fluid to the larger end of said converging nozzlesection for flow through said sections, the pressure of said workingfluid at the entrance to the converging nozzle section being sufficientto accelerate the mixture to attain sonic velocity at the downstream endof the throat section, the throat section being long enough to assuremaximum transfer of kinetic energy from the fluid to the solids.

1. AN APPARATUS FOR REDUCING THE SIZE OF SHOCK-SEVERABLE MATERIALCOMPRISING, A FIRST VESSEL FOR RECEIVING THE MATERIAL AND DEFINING AFIRST ZONE, A SECOND VESSEL DEFINING A SECOND ZONE A DUCT EXTENDING FROMTHE FIRST VESSEL TO THE SECOND VESSEL, A QUICK OPENING VALVE IN SAIDDUCT, MEANS FOR INTRODUCING A PREDETERMINED AMOUNT OF A COMPRESSIBLEWORKING FLUID INTO THE FIRST VESSEL INCLUDING AN INLET IN SAID DUCTADJACENT TO SAID VALVE FOR INTRODUCING AT LEAST A SUBSTANTIAL PORTION OFSAID PREDETERMINES AMOUNT FOR CARRYING ANY OF SAID MATERIAL IN HE DUCTBACK TO THE FIRST VESSEL. MEANS FOR CLOSING SAID VALVE DURING THEINRODUCTION OF SAID FLUID INTO THE FIRST ZONE, MEANS FOR OPENING THEVALVE SUDDENLY TO DISCHARGE A MIXED STREAM OF WORKING FLUID AND MATERIALFROM SAID FIRST VESSEL INTO THE DUCT WHICH CONDUCTS SAID STREAM TO THESECOND VESSEL, MEANS LOCATED BETWEEN THE FIRST VESSEL AND DUCT FORCREATING A ZONE WHEREIN THE SOLID MATERIAL IS SUBJECTED TO SHOCKPHENOMENA AS IT EXITS FROM THE FIRST VESSEL AND ENTERS SAID DUCT TOTHEREBY SHATTER AND REDUCE THE SIZE OF SAID MATERIAL, SAID QUICK-OPENINGVALVE BEING LOCATED A PREDETERMINED DISTANCE FROM THE FIRST VESSEL ANDTHE SPACING OF THE VALVE FROM FIRST VESSEL AND THE TIME OF OPENING SAIDVALVE BEING SUCH THAT SAID VALVE MOVES TO FULLY OPEN POSITION BEFORE THEMATERIAL DISCHARGED FROM SAID FIRST VESSEL REACHES SAID VALVE.
 2. Themethod of reducing the size of shock-severable solids comprising,introducing a charge of said solids into a pressure vessel, introducinga compressible working fluid into the pressure vessel until apreselected pressure is attained in said vessel, directing a mixedstream of the working fluid and solids into a continuous nozzle systemwhich extends from said pressure vessel to an impact chamber through thesuccessive steps of converging the mixed stream in a converging sectionof the nozzle system, thereby accelerating the working fluid portion ofthe mixed stream relative to the solids, directing the mixed streamthrough an elongated throat section of the nozzle system having aconstant area equal to the minimum area of the converging section and alength sufficient to accelerate the solids of the mixed stream relativeto the working fluid portion until maximum kinetic energy has beentransferred from the working fluid to the solids and the stream reachesthe sonic velocity of the fluid-solids mixture; diverging the mixedstream approximately isentropically at supersonic velocities in adiverging section of the nozzle system and discharging the mixed streamof working fluid and solids as a free jet into the impact chamber afterpassage through the nozzle system, the pressure in the impact chamberremaining approximately constant.
 3. The method set forth in claim 2,with the additional step of impacting the solids in the free jet againsta rigid surface within the impact chamber.
 4. The method set forth inclaim 2 further comprising the step of separating the lighter solids andboundary layer of fluid from the central portion of the mixed streamdischarging as a free jet into the impact chamber by flow over a Coandasurface connected to the downstream end of the diverging section of thenozzle system.
 5. The method set forth in claim 2, further comprisingthe step of directing the mixed stream of working fluid and solids fromthe pressure vessel into the nozzle system through an eccentric lowerend of said pressure vessel.
 6. The method set forth in claim 2comprising the further step of discharging the mixed stream of fluid andsolids from the impact chamber into a cyclone separator through adivergent passage to decelerate the flow.
 7. The method set forth inclaim 2, wherein at least a substantial portion of the total workingfluid introduced into the pressure vessel is introduced through an inletinto the nozzle system downstream from the converging section.
 8. Themethod of reducing the size of shock-severable solids comprising,introducing a charge of said solids into a pressure vessel, introducinga compressible working fluid into the pressure vessel until apreselected pressure is attained in said vessel, releasing a mixedstream of working fluid and entrained solids from said vessel into anozzle system which extends from said pressure vessel to a chamber, saidnozzle system comprising successively a converging section, an elongatedthroat section and a diverging section, said system functioning torapidly accelerate the working fluid and less rapidly accelerate saidentrained solids to create shock phenomena as the working fluid andsolids pass through the converging section, said elongated throatsection having a length sufficient for the fluid to transfer maximumkinetic energy to the solids entrained therein and to accelerate thesolids to the sonic velocity of the mixture as the mixed stream of fluidand solids flows through the elongated throat section, said systemfunctioning to further accelerate the fluid and solids as the mixtureflows through the diverging section, and discharging the mixed stream offluid and solids as a free jet into a chamber after passage through thenozzle system for subjecting the material to further shock phenomena. 9.The method set forth in claim 8 comprising the additional step ofimpacting the solids against a rigid surface within the chamber.
 10. Themethod set forth in claim 8 further comprising the step of separatingthe lighter solids and boundary layer of fluid from the central portionof the mixed stream discharging as a free jet into the chamber by flowover a Coanda surface connected to the terminus of the diverging sectionof the nozzle system.
 11. The method set forth in claim 8 furthercomprising the step of discharging the mixed stream of working fluid andsolids into the nozzle system from the pressure vessel through aneccentric lower end of said pressure vessel.
 12. The method set forth inclaim 8 comprising the further step of discharging the mixed stream offluid and solids from the chamber into a cyclone separator through adivergent passage to decelerate the flow.
 13. The method set forth inclaim 8, wherein at least a substantial portion of the working fluidintroduced into the pressure vessel is introduced through an inlet intothe nozzle system downstream from the converging section.
 14. The methodof reducing the size of particles of a shock-severable solid materialcharged into a pressure vessel comprising, adding to the solid particlesa predetermined quantity of a compressible working fluid in the pressurevessel until a predetermined pressure is attained suddenly expanding astream of the working fluid and solids from said vessel into acontinuous nozzle system which extends from the pressure vessel to achamber so that the particles of solid material are entrained in thefluid stream, said nozzle system comprising a converging section, anelongated throat section and a diverging section, directing the streamfrom the pressure vessel through said converging section of the nozzlesystem for increasing the velocity of the working fluid to a maximumvalue at the entrance to the elongated throat section to generate shockwaves which act upon the particles of said material to reduce theirsize, directing the mixed fluid and solid stream through said elongatedthroat section until maximum possible transfer of kinetic energy fromthe fluid to the solid particles has been achieved, the velocity of thecombined polyphase fluid and solid mixture attaining the sonic velocityof said mixture at the downstream end of the throat section, anddirecting the mixed stream through the section into a chamber foraccelerating the fluid and the solid particles in the mixed stream tosupersonic velocities said chamber having a sufficiently large exit areato permit free expansion of said fluid with minimal stagnation pressurein said chamber.
 15. The method set forth in claim 14 wherein theelongated throat section has a substantially constant cross-sectionalarea.
 16. The method of reducing the size of particles of ashock-severable solid material comprising, entraining said particles ina stream of compressible working fluid, accelerating said fluid at afaster rate than said particles within a converging boundary surface,then further accelerating said particles and decelerating said fluidwithin an elongated continuation of said boundary surface havingsubstantially constant cross section until maximum transfer of kineticenergy from the fluid to the solid particles has been achieved and thevelocities of the particles and fluid are substantially equal to thetwo-phase sonic velocity of said mixed stream, then still furtheraccelerating said fluid and said particles to supersonic velocities in adiverging continuation of said boundary surface, and discharging saidparticles and fluid into a chamber, whereby said particles will besubject to shock phenomena at each stage of acceleration of saidparticles.
 17. The method of reducing the size of shock-severable solidscomprising, introducing a charge of said solids into a first pressurevessel, introducing a compressible working fluid of predeterminedquantity and pressure into the pressure vessel, directing a mixed streamof fluid and solids into a first nozzle system which extends from saidpressure vessel to an impact chamber maintained at approximately saidsecond pressure, said first nozzle system comprising a convergingsection, an elongated throat section and a diverging section, the lengthof the throat section being sufficient to permit maximum transfer ofkinetic energy from the fluid to the solids so that the velocities ofsaid fluid and solids equal the sonic velocity in the mixed stream atthe downsteam end of the throat section, subjecting the stream to shockphenomena as it flows from the pressure vessel to the impact chamber,discharging said stream as a free jet into said impact chamber at a highvelocity, introducing a charge of said solids into a second pressurevessel, introducing a coMpressible working fluid of predeterminedquantity and pressure into the second pressure vessel, directing a mixedstream of fluid and solids into a second nozzle system which extendsfrom said second pressure vessel to the impact chamber, said secondsystem comprising a converging section, an elongated non-divergentthroat section and a diverging section, the length of the throat sectionbeing sufficient to permit maximum transfer of kinetic energy from thefluid to the solids so that the velocities of said fluid and solidsequal the sonic velocity in the mixed stream at the downstream end ofthe throat section, subjecting the stream to shock phenomena as itexpands at supersonic velocity through the diverging section to theimpact chamber, discharging said stream as a free jet into said impactchamber at a high velocity, and selectively impacting the coarserportion of the solids discharging from the first system against asimilar portion of the solids discharging from the second system tofurther reduce the size of the solids.
 18. The method set forth in claim17, with the additional step of deflecting the finer portion of thesolids and the boundary portion of the working fluid discharging as freejets from the diverging sections of the nozzle systems radiallyoutwardly and away from the impact zone by means of Coanda surfaces. 19.The method set forth in claim 17, wherein said solids are subjected tosaid shock phenomena as they pass through said nozzle systems bydirecting said solids through said converging sections which direct theflow from the pressure vessels into the elongated throat sections, andsaid solids are subjected to further shock phenomena in the region ofthe exits from the systems by directing said solids through saiddiverging sections which direct the flow from said throat sections intothe impact chamber.
 20. The method of claim 17, wherein the impactchamber has a sufficiently large exit area to permit free egress of saidfluid, with no general increase of the pressure in said chamber.
 21. Anapparatus for reducing the size of particles of a shock-severable solidmaterial comprising, a pressure vessel for receiving the particles, animpact chamber, a system extending from the pressure vessel to theimpact chamber, said system comprising a convergent nozzle section, anelongated throat section and a divergent nozzle section opening into theimpact chamber, a quick-opening valve in said system, means forintroducing a predetermined amount of a compressible working fluid intothe pressure vessel when the valve is closed that is sufficient tocreate sonic flow at the downstream end of the elongated throat sectionof a mixed stream of working fluid and particles of material when thevalve is opened, the length of the elongated throat section beingsufficient to permit maximum transfer of kinetic energy from the fluidto the particles of solid material in the mixed stream, and means foropening the valve to suddenly discharge a mixed stream of working fluidand particles of solid material from said vessel through the systemwherein shock phenomena act to shatter and reduce the size of saidmaterial.
 22. An apparatus as set forth in claim 21 comprising adischarge passage from the pressure vessel eccentric to the principalaxis of said vessel connecting the pressure vessel to the larger end ofthe convergent nozzle section.
 23. An apparatus as set forth in claim21, wherein the valve is positioned in the elongated throat section andthe means for introducing a compressible working fluid into the pressurevessel comprises an inlet duct connected into the system between thevalve and the convergent nozzle section.
 24. An apparatus as set forthin claim 23, wherein the means for introducing a compressible workingfluid comprises two ducts entering said system in opposed relationship.25. An apparatus as set forth in claim 21 further comprising a CoaNdasurface forming a smoothly flaring connection between the outlet of thedivergent nozzle section and the impact chamber.
 26. An apparatus as setforth in claim 21 further comprising a separator and a divergent passageconnecting the impact chamber to the separator for decelerating thefluid passing from the impact chamber to the separator.
 27. An apparatusas set forth in claim 21, wherein said convergent nozzle section has itslarger end connected with the pressure vessel and its smaller endconnected with the throat section, the length and configuration of theconvergent nozzle section being such that after introducing saidpredetermined amount of compressible fluid into the pressure vessel andupon opening of the valve, the working fluid expands to attain avelocity sufficient to cause local zones of supersonic flow attached tothe slower moving solid particles whereby the solids are subjected toshock phenomena resulting from the perturbation of said local zones ofsupersonic flow.
 28. An apparatus as set forth in claim 21, wherein saidelongated throat section is of substantially constant cross-sectionalarea throughout its length, and the divergent nozzle section connectsthe throat section with the impact chamber and is constructed to furtherincrease the velocity of the stream as the mixed stream is dischargedinto the impact chamber.
 29. An apparatus for reducing the size ofshock-severable solids comprising, a convergent nozzle section, anelongated throat section of constant area having one end connected tothe smaller end of the convergent section, a divergent nozzle sectionhaving its smaller end connected to the other end of the throat section,and means for supplying a subsonic stream of said solids entrained in acompressible working fluid to the larger end of said convergent nozzlesection for flow through said sections, the pressure of said workingfluid at the entrance of the convergent nozzle section being sufficientto accelerate the mixture to attain sonic velocity at the downstream endof the throat section, the throat section being long enough to assuremaximum transfer of kinetic energy from the fluid to the solids, and thedivergent nozzle section being constructed to accelerate the mixedstream to supersonic velocities.
 30. An apparatus for reducing the sizeof a shock-severable material comprising, a pressure vessel forreceiving the material, an impact chamber, a system extending from thepressure vessel to the impact chamber, a quick-opening valve in saidsystem, means for introducing a compressible working fluid into thepressure vessel, said valve being in closed position during theintroduction of said fluid into the pressure vessel, means for openingthe valve to suddenly discharge the mixed stream of working fluid andmaterial into the system which conducts said stream to the impactchamber, means located in the system downstream of the pressure vesseladapted to subject the solid material to shock phenomena to therebyshatter and reduce the size of said material, said quick-opening valvebeing located a predetermined distance from the pressure vessel, thecompressible working fluid being introduced into the system between saidvalve and said pressure vessel, whereby such working fluid flows intothe vessel through the system in a direction opposite to that in whichthe material is discharged from said vessel, and the spacing of thevalve frorm said pressure vessel and the time of opening of said valvebeing such that said valve moves to fully open position before any ofthe material discharged from said pressure vessel reaches said valve.31. An apparatus for reducing the size of particles of a shock-severablesolid material comprising, first and second pressure vessels forreceiving the particles of material, an impact chamber positionedbetween the pressure vessels, a separate nozzle system extending fromeach Pressure vessel to the impact chamber with the axis of one systemintersecting the axis of the other system in the impact chamber, eachsystem comprising in continuous succession a converging section, anelongated constant area throat section and a diverging section, aquick-opening valve in each of said systems, means for introducing acompressible working fluid into each of said vessels while said valvesare closed, and means for simultaneously opening the valves to suddenlydischarge mixed streams of working fluid and material from each of thepressure vessels through the respective systems into the impact chamberfrom opposing directions, the pressure of said working fluid at theentrance of the convergent nozzle section being sufficient to acceleratethe mixture to attain sonic velocity at the downstream end of the throatsection, the throat section being long enough to assure maximum transferof kinetic energy from the fluid to the particles of solid material, andthe divergent nozzle section being constructed to accelerate the mixedstream to supersonic velocities for discharge as a free jet into theimpact chamber, whereby shock phenomena shatter and reduce the size ofsaid particles in the nozzle systems and further reduction of the sizeof the particles is caused by collision of the interseting streams ofparticles discharged from the two nozzle systems in the impact chamber.32. An apparatus as set forth in cliam 31 further comprising dischargepassages from the pressure vessels to the respective nozzle systems thatare eccentric to the principal axis of each of said vessels.
 33. Anapparatus as set forth in claim 31, wherein the quick-opening valves arepositioned in the elongated throat sections of each system and the meansfor introducing a compressible working fluid into the pressure vesselsis comprised of inlet ducts opening into the systems between the valvesand the convergent nozzle sections.
 34. An apparatus as set forth inclaim 33, wherein said fluid inlet ducts comprise at least two ductsopening into each nozzle system in opposed relationship to reduceerosion from wire-drawing by the incoming fluid.
 35. An apparatus as setforth in claim 31 further comprising Coanda surfaces between the ends ofthe divergent nozzle sections and the impact chamber.
 36. An apparatusas set forth in claim 31 further comprising a separator and a divergentpassage connecting the impact chamber to the separator for deceleratingthe fluiid and solid particles passing from the impact chamber to theseparator.
 37. An apparatus as set forth in claim 31 further comprisingtwo deflector plates spaced from the discharge end of each nozzle systemand located in said impact chamber, each deflector plate having acentral opening so that the particles in the central portion of onedischarged jet may collide with the particles in the central portion ofthe other jet while the remainder of each jet is deflected away from thecollision region.
 38. A method of reducing the size of shock severablesolids comprising the steps of: entraining particles of said solids in astream of compressible working fluid surrounded by a cylindricalboundary surface; directing the mixed stream of fluid and solidparticles through a converging boundary surface, thereby acceleratingthe fluid at a faster rate than the solids; then directing the mixedstream in a straight line through an elongated cylindrical boundarysurface equal in cross section to the downstream end of the convergingboundary surface until maximum transfer of kinetic energy from the fluidto the solid particles has been achieved and the velocities of theparticles and fluid are substantially equal to the two-phase sonicvelocity of said mixed stream, and discharging said particles and fluidinto a chamber.
 39. An apparatus for reducing the size ofshock-severable solids comprising: a converging nozzle section, anelongated throat section of constant Area extending in a straight linefrom the smaller end of the converging nozzle section, and means forsupplying a subsonic stream of said solids entrained in a compressibleworking fluid to the larger end of said converging nozzle section forflow through said sections, the pressure of said working fluid at theentrance to the converging nozzle section being sufficient to acceleratethe mixture to attain sonic velocity at the downstream end of the throatsection, the throat section being long enough to assure maximum transferof kinetic energy from the fluid to the solids.